You're welcome. The search on Tower Hobbies only hits on exact matches.
Like they listed the B4 as RC10B4. So you search on 'B4 chassis' and you don't get what you want. You search for 'RC10B4 chassis' and you get the right results. Then to confuse matters you think, Hey I'll search for 'RC10T4 chassis', well that gets you nothing. You have to search for 'T4 chassis' to get the right results.
I actually cheated and went to the parts manual and searched by the part number first.